Peritoneal Cell-Derived Exosomes: Novel Mediators of T Cell Activation and Vaccine Potency in Fish

ABSTRACT: Exosomes are small extracellular vesicles that play significant roles in cell communication and immune modulation. When considering adaptive immunity, exosomes have been proposed to be involved in T and B cell development, antigen presentation, as well as the cross-presentation of antigens. While the potential of exosomes to carry vaccine-relevant antigens has been discussed, their intrinsic properties in activating adaptive immune responses have not yet been fully addressed. To explore these roles further, this study utilizes a fish model to examine the detailed effects of exosomes. We demonstrate that the peritoneal cells derived exosomes (PDEs), which fuse with cells in the peritoneum, carry and transport antigen presentation molecules locally. Additionally, PDEs are transferred from the peritoneum and accumulate in critical lymphoid organs, including the head kidney and spleen. Notably, PDEs effectively promoted Cd4-1+ and Cd4-2+ T cells activation in both in vivo and in vitro settings following exposure of cells to the PDEs. The experimental outcomes have indicated an increased level of Mhcii+ and Cd80/86+ exosomes secreted from peritoneal cells of fish vaccinated with Vibrio anguillarum via intraperitoneal injection, accompanied by the carriage of T cell-associated RNA and miRNA cargos. Moreover, the intraperitoneal injection of endogenous exosomes derived from Vibrio anguillarum-elicited cells enhanced vaccine potency by promoting antibody production. This study provides a novel avenue wherein exosomes are directly involved in vaccine-induced immunity, as evidenced in a lower vertebrate. It is plausible that such events and processes may also prevail in higher vertebrates, such as in humans.

INSTRUMENT(S):

ORGANISM(S): Paralichthys Olivaceus

TISSUE(S): Peritoneal Fluid

SUBMITTER: xueyan shi  

LAB HEAD: Xueyan Shi

PROVIDER: PXD059066 | Pride | 2026-04-06

REPOSITORIES: Pride